The movie shows an ASC simulation of the atomic level deformation of copper around a growing void. Void growth and coalescence are known to be the microscopic mechanism of fracture in ductile metals like copper. The goal of these simulations is to characterize how the material must deform to accommodate the growing void. The simulation consisted of a cube of single crystal copper with periodic boundary conditions and a small void present initially in the material. The size of the box was then increased, inducing a tensile stress, at a rate comparable to the strain rate in tensile (release) shock waves. The movie shows only those atoms that are doing something interesting: the atoms on the surface of the void and those in crystal defects associated with the deformation. These defects, known as dislocations, form on the surface of the void and propagate away as loops. The loops appear as parallelograms in the movie. The coloring indicates the distance from the center of the void. The loop mechanism transports atoms away from the void allowing it to grow.
